U.S. patent application number 16/374429 was filed with the patent office on 2019-10-10 for pixel configuration and surface treatment in a transparent display.
This patent application is currently assigned to NanoPath, Inc.. The applicant listed for this patent is NanoPath, Inc.. Invention is credited to Kevin Donahue.
Application Number | 20190310412 16/374429 |
Document ID | / |
Family ID | 66175567 |
Filed Date | 2019-10-10 |
United States Patent
Application |
20190310412 |
Kind Code |
A1 |
Donahue; Kevin |
October 10, 2019 |
PIXEL CONFIGURATION AND SURFACE TREATMENT IN A TRANSPARENT
DISPLAY
Abstract
A one-way see-through illumination device includes a light
guide, a light source at an edge of the light guide and a pattern
of pixels on a surface of the light guide. The light guide has an
illumination surface and a non-illumination surface opposite to the
illumination surface. The light source is configured to inject
light into the edge of the light guide. The pattern of pixels and
the light guide are arranged to generate transparent illumination
by the frustration of total internal reflection of light injected
into the light guide such that light from the light source is
emitted through the illumination surface. The pixels are arranged
to prevent the generation of a diffraction grating in the light
guide.
Inventors: |
Donahue; Kevin; (Harvard,
MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NanoPath, Inc. |
Leominster |
MA |
US |
|
|
Assignee: |
NanoPath, Inc.
Leominster
MA
|
Family ID: |
66175567 |
Appl. No.: |
16/374429 |
Filed: |
April 3, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62652383 |
Apr 4, 2018 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B 2027/0116 20130101;
G02B 6/0055 20130101; G02B 27/0172 20130101; G02B 27/0101 20130101;
G02B 6/0065 20130101; G02B 6/0058 20130101; G02B 6/0051 20130101;
G02B 2027/0118 20130101 |
International
Class: |
F21V 8/00 20060101
F21V008/00 |
Claims
1. A one-way see-through illumination device, comprising a light
guide having an illumination surface and a non-illumination surface
opposite to the illumination surface; a light source at an edge of
the light guide, and configured to inject light into the edge of
the light guide; and a pattern of pixels on a surface of the light
guide, wherein the pattern of pixels and the light guide are
arranged to generate transparent illumination by the frustration of
total internal reflection of light injected into the light guide
such that light from the light source is emitted through the
illumination surface, wherein the pixels are arranged to prevent
the generation of a diffraction grating in the light guide.
2. The one-way see-through illumination device of claim 1, wherein
the pixels have a width less than one micron.
3. The one-way see-through illumination device of claim 1, wherein
the pixels are disposed in a non-uniform manner.
4. The one-way see-through illumination device of claim 3, wherein
the pixels have a width less than one micron.
5. The one-way see-through illumination device of claim 3, wherein
the pixels have various different widths.
6. The one-way see-through illumination device of claim 3, wherein
the pixels have various different depths.
7. The one-way see-through illumination device of claim 3, wherein
the pixels have various spacings between pixels.
8. The one-way see-through illumination device of claim 3, wherein
the pixels have various pixel shapes.
9. The one-way see-through illumination device of claim 3, wherein
the pixels have various pixel densities.
10. The one-way see-through illumination device of claim 1, wherein
the pixels include a light diffusing layer and a light reflecting
layer.
11. The one-way see-through illumination device of claim 1, wherein
the pattern of pixels comprises a maximum pixel width of less than
15 microns.
12. A one-way see-through illumination device, comprising a light
guide having an illumination surface and a non-illumination surface
opposite to the illumination side; a light source at an edge of the
light guide, and configured to inject light into the edge of the
light guide; a pattern of pixels on a surface of the light guide,
wherein the pattern of pixels and the light guide are arranged to
generate transparent illumination by the frustration of total
internal reflection of light injected into the light guide such
that light from the light source is emitted through the
illumination surface; and an antireflection coating disposed on the
illumination surface to reduce reflection of light from the pixels
directed to the illumination surface.
13. The one-way see-through illumination device of claim 12,
wherein the pixels include a light diffusing layer and a light
reflecting layer.
14. A method of forming a one-way see-through illumination device
including a light guide having an illumination surface and a
non-illumination surface opposite to the illumination surface and a
pattern of pixels on the non-illumination surface of the light
guide, the method comprising: forming pixel wells corresponding to
the pixels on the non-illumination surface; and forming the pixels
using the pixel wells, wherein the pattern of pixels and the light
guide are arranged to generate transparent illumination by the
frustration of total internal reflection of light injected into the
light guide, wherein the pixels are arranged to prevent the
generation of diffraction grating in the light guide.
15. The method of claim 14, wherein the pixels include a light
diffusing layer and a light reflecting layer.
16. The method of claim 15, wherein the light diffusing layer
includes titanium dioxide and an optically clear polymer.
17. The method of claim 15, wherein the pixel pattern is such that
the pixels are disposed in a non-uniform manner.
18. The method of claim 15, wherein the pixel pattern is such that
the pixels are disposed in a random manner.
19. The method of claim 18, further comprising selecting a
placement of the pixels of the pixel pattern such that the pixels
do not overlap each other.
20. The method of claim 15, wherein pixels have a width less than
15 microns.
Description
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Application Ser. No. 62/652,383 filed Apr. 4, 2018, entitled "PIXEL
CONFIGURATION AND SURFACE TREATMENT IN A TRANSPARENT DISPLAY,"
incorporated by reference herein in its entirety.
FIELD OF DISCLOSURE
[0002] Systems and methods for displays are described using pixel
placement.
BACKGROUND
[0003] One-way see-through illumination, also called transparent
illumination, may be used in planar light guides including:
eyeglass lenses, signs and windows. For example, U.S. patents, U.S.
Pat. Nos. 8,511,884, 7,513,674 and 8,100,575 describe various
implementations for rendering one-way see-through illumination.
[0004] In the above identified patents, pixels that emit light in
one direction are applied to the surface of an active light guide.
These pixels are composed of a layer of light diffusing material
that is capped by a metallic reflector. The light diffusing layer
in each pixel emits light by frustrating total internal reflection.
Each pixel's metallic cap then prevents light from being emitted
through the non-illuminated side of the light guide causing
transparent illumination. Ultimately, to achieve a fully
transparent illumination (meaning no trace of illumination or pixel
structures on the non-illuminated side of the light guide),
microscopic/invisible pixels are required to prevent the perception
of a pixel pattern especially in applications such as eyeglasses.
For example, in an eyeglass application of transparent illumination
in which the exterior of each eyeglass lens is illuminated, pixels
greater than 15 microns in width can be perceived by the human eye,
thus distorting or impeding vision. Thus, to promote "invisible"
transparent illumination, invisible pixels, i.e. pixels less than
15 microns in width, are deployed. Arrays of micron scale pixels,
however, regardless of their geometric shape, often cause
diffraction gratings. These diffraction gratings separate
composite/ambient light into its components causing a rainbow
effect that distorts vision when viewing an object through a
transparent display.
SUMMARY
[0005] According to inventive concepts disclosed herein, there is
provided a one-way see-through illumination device. The device
comprises a light guide, a light source at an edge of the light
guide and a pattern of pixels on a surface of the light guide. The
light guide has an illumination surface and a non-illumination
surface opposite to the illumination surface. The light source is
configured to inject light into the edge of the light guide. The
pattern of pixels and the light guide are arranged to generate
transparent illumination by the frustration of total internal
reflection of light injected into the light guide such that light
from the light source is emitted through the illumination surface.
The pixels are arranged to prevent the generation of a diffraction
grating in the light guide.
[0006] According to one aspect according to inventive concepts
disclosed herein, the pixels have a width less than one micron.
[0007] According to one aspect according to inventive concepts
disclosed herein, the pixels are disposed in a non-uniform
manner.
[0008] According to one aspect according to inventive concepts
disclosed herein, the pixels have a width less than one micron.
[0009] According to one aspect according to inventive concepts
disclosed herein, the pixels have various different widths.
[0010] According to one aspect according to inventive concepts
disclosed herein, the pixels have various different depths.
[0011] According to one aspect according to inventive concepts
disclosed herein, the pixels have various spacings between
pixels.
[0012] According to one aspect according to inventive concepts
disclosed herein, the pixels have various pixel shapes.
[0013] According to one aspect according to inventive concepts
disclosed herein, the pixels have various pixel densities.
[0014] According to one aspect according to inventive concepts
disclosed herein, the pixels include a light diffusing layer and a
light reflecting layer.
[0015] According to one aspect according to inventive concepts
disclosed herein, the pattern of pixels comprises a maximum pixel
width of less than 15 microns.
[0016] According to inventive concepts disclosed herein, there is
provided a one-way see-through illumination device. The device
comprises a light guide, a light source at an edge of the light
guide, a pattern of pixels on a surface of the light guide, and an
antireflection coating. The light guide has an illumination surface
and a non-illumination surface opposite to the illumination side.
The light source is configured to inject light into the edge of the
light guide. The pattern of pixels and the light guide are arranged
to generate transparent illumination by the frustration of total
internal reflection of light injected into the light guide such
that light from the light source is emitted through the
illumination surface. The antireflection coating is disposed on the
illumination surface to reduce reflection of light from the pixels
directed to the illumination surface.
[0017] According to one aspect according to inventive concepts
disclosed herein, the pixels include a light diffusing layer and a
light reflecting layer.
[0018] According to inventive concepts disclosed herein, there is
provided a method of forming a one-way see-through illumination
device including a light guide having an illumination surface and a
non-illumination surface opposite to the illumination surface and a
pattern of pixels on the non-illumination surface of the light
guide. The method comprises: forming pixel wells corresponding to
the pixels on the non-illumination surface; and forming the pixels
using the pixel wells, wherein the pattern of pixels and the light
guide are arranged to generate transparent illumination by the
frustration of total internal reflection of light injected into the
light guide. The pixels are arranged to prevent the generation of
diffraction grating in the light guide.
[0019] According to one aspect according to inventive concepts
disclosed herein, the pixels include a light diffusing layer and a
light reflecting layer.
[0020] According to one aspect according to inventive concepts
disclosed herein, the light diffusing layer includes titanium
dioxide and an optically clear polymer.
[0021] According to one aspect according to inventive concepts
disclosed herein, the pixel pattern is such that the pixels are
disposed in a non-uniform manner.
[0022] According to one aspect according to inventive concepts
disclosed herein, the pixel pattern is such that the pixels are
disposed in a random manner.
[0023] According to one aspect according to inventive concepts
disclosed herein, the method further comprises selecting a
placement of the pixels of the pixel pattern such that the pixels
do not overlap each other.
[0024] According to one aspect according to inventive concepts
disclosed herein, the pixels have a width less than 15 microns.
[0025] According to one aspect according to inventive concepts
disclosed herein, there is provided a photoresist exposure mask
with transparent areas less than twenty microns in width with
random locations across a surface area of a transparent substrate
that has a surface area that exceeds 400 square millimeters.
[0026] According to one aspect according to inventive concepts
disclosed herein, there is provided a method of generating random
locations upon the photoresist exposure mask wherein locations are
specified by randomly searching for available locations based upon
pixel size, pixel spacing, or pixel density.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Implementations of the inventive concepts disclosed herein
may be better understood when consideration is given to the
following detailed description thereof. Such description makes
reference to the included drawings, which are not necessarily to
scale, and in which some features may be exaggerated and some
features may be omitted or may be represented schematically in the
interest of clarity. Like reference numerals in the drawings may
represent and refer to the same or similar element, feature, or
function. In the drawings:
[0028] FIG. 1 is a side view illustrating a one-way see-through
illumination device of an embodiment according to inventive
concepts disclosed herein.
[0029] FIG. 2 is a top view illustrating a one-way see-through
illumination device with a non-uniform width and size of pixels
according to inventive concepts disclosed herein.
[0030] FIG. 3 is a side view illustrating a one-way see-through
illumination device with a non-uniform depth of pixels according to
inventive concepts disclosed herein.
[0031] FIG. 4 is a top view illustrating a one-way see-through
illumination device with a non-uniform shape of pixels according to
inventive concepts disclosed herein.
[0032] FIG. 5 is a side view illustrating a one-way see-through
illumination device having an antireflection coating on the
illumination surface according to inventive concepts disclosed
herein.
[0033] FIG. 6A is a side view illustrating a one-way see-through
illumination device having a uniform arrangement of pixels.
[0034] FIG. 6B is a top view of the one-way see-through
illumination device of FIG. 6A.
DETAILED DESCRIPTION
[0035] Displays are described using non-uniform or random,
non-overlapping, pixel placement of micron scale pixels to deter
the generation of diffraction gratings for the purpose of vision
clarity. The disclosed arrangement of pixels provides for the use
of invisible one-way light-emitting pixels and avoidance of
diffraction gratings. The arrangement uses non-uniform or random,
non-overlapping, pixel placement of micron scale pixels to deter
the generation of diffraction gratings for the purpose of vision
clarity.
[0036] According to another aspect of the display, optimal night
usage of transparent illumination is achieved by the application of
an anti-reflection coating or coatings to the illumination surface.
The anti-reflection coating prevents perceptible illumination of
the non-illumination surface of the transparent display. This may
be achieved, for example, by a Fresnel defined mirror reflection
from the illuminated surface of the transparent display.
[0037] FIG. 6A is a side view illustrating a one-way see-through
illumination device 600 which may be susceptible to the generation
of diffraction grating in the light guide. FIG. 6B is a top view of
the one-way see-through illumination device 600 of FIG. 6A,
illustrating further portions of the device 600 seen having a
larger number of pixels than shown in FIG. 6A. FIG. 6A illustrates
only two pixels 120 for ease of illustration. The illumination
device 600 includes a light guide 110, a light source 130, and a
pattern of pixels 120 on a non-illumination surface 140 of the
light guide 110. Each the pattern of pixels 120 includes a light
diffusing layer 124 and a light reflecting layer 122. The
illumination device 100 further includes an illumination surface
142 of the light guide 110 opposite to the non-illumination surface
140.
[0038] Some of the light, but not all, originally emitted from the
light source 130 is ultimately directed (by the frustration of
total internal reflection by the pixel surface) to the
non-illumination surface 140 and exits the illumination surface
142. On the other hand, light originally emitted from the light
source 130 which does impinge on a pixel 120 is directed to the
illumination surface 142, and is totally internally reflected and
thus does not exit the illumination surface 142 or the
non-illumination surface 140. Thus, the eye 150 of a viewer which
is on the side of the illumination surface 142 is able to view
light originating from the light source 130 and injected into the
light guide 110. On the other hand, the eye 150 of a viewer, if the
eye 150 is on the side of the non-illumination surface 140, is not
able to view light originating from the light source 130 and
injected into the light guide 110. Thus, the light originating from
the light source 130 and injected into the light guide 110 appears
to be invisible from the non-illumination surface 140.
[0039] A light ray 132 is emitted from the light source 130 and
directed into the light guide 110 at an angle such that the light
ray 132 impinging on the non-illumination surface 140 or
illumination surface 142 undergoes total internal reflection, and
the light ray 132 stays within the light guide 110. The light
diffusing layer 124 is chosen to be made of a light diffusing
material which has an index of refraction such that when the light
ray 132 originally emitted from the light source 130 impinges on
the light diffusing layer 124, total internal reflection does not
occur, and the light ray 132 is transmitted into the light
diffusing layer 124. The light ray 132 transmitted into the light
diffusing layer 124 is diffused and impinges on the light
reflecting layer 122, where the light ray 132 is reflected back
into the light diffusing layer 124 and is further diffused. The
reflected and diffused light from the light diffusing layer 124
then exits the light diffusing layer 124, and impacts the
illumination surface 142 at less than the critical angle such that
the light exits the light guide 110, and can be seen.
[0040] The one-way see-through illumination device 600 may be
susceptible to the generation of diffraction grating in the light
guide made up of pixels 120, and thus the illumination device 600
may be subject to the rainbow effect from white light impinging on
the illumination surface 142 from outside of the device 600. For
example, for an outside light source 1010, such as the sun, which
provides white light impinging upon the illumination surface 142
from outside of the device 600, the uniform disposition and size of
the pixels 120 provide a grating. When the sunlight passes between
the pixels the white light from the sun experiences wave
interference and a visible rainbow effect 1020 occurs that impedes
vision from the interior (non-illuminated) side of the display
600.
[0041] The diffraction grating results from the uniform disposition
and size of the pixels 120 as shown in FIGS. 6A and 6B. Thus, in
order to prevent the pixels 120 from generating a diffraction
grating, the pixels should be arranged in a non-uniform fashion. In
this regard, the pixels may be arranged to have a non-uniform pixel
width, spacing between pixels, pixel depth, pixel shape, pixel
density and/or pixel placement.
[0042] FIG. 1 is a side view illustrating a one-way see-through
device 100 according to the inventive concepts disclosed herein
where the pixels 120 have a non-uniform pixel arrangement. FIG. 2
illustrates a top view of the one-way see-through device 100 of
FIG. 1, where a further portion of the device seen in FIG. 2 can be
seen having a larger number of pixels 120 than in FIG. 1. FIG. 1
illustrates only two pixels 120 for ease of illustration.
Specifically, as can be seen in FIG. 2 the spacing between pixels
120, both in the vertical V and horizontal H direction of FIG. 2,
is non-uniform, and the spacing and density changes both in the
vertical V and horizontal H directions in FIG. 2.
[0043] The light diffusing layer 124 of each pixel 120 may include
a metal oxide within a optically clear material. For example, the
light diffusing layer 124 of each pixel 120 may include titanium
dioxide within an optically clear polymer.
[0044] The light reflecting layer 122 of each pixel 120 may include
a reflecting material, such as a metal. For example, the light
diffusing layer 124 of each pixel 120 may include a metal, such as
aluminum, for example.
[0045] Methods for generating invisible one-way light-emitting
pixels may include micron-scale and/or nanoscale material
deposition processes including but not limited to the following
processes of nanoprinting, including nanoassembly of nanoparticles
in nanoimprinted wells, micromachining, such as laser cutting
micron-scale features, and photolithography.
[0046] FIG. 2 illustrates a top view of the one-way see-through
device 100 with a non-uniform arrangement of the pixels 120.
Specifically, as can be seen in FIG. 2 the width W and size of the
pixels 120, is non-uniform. The non-uniform arrangement of the
pixels 120 deters the generation of diffraction gratings by the
pixels 120.
[0047] FIG. 3 illustrates a side view of the one-way see-through
device 100 with a non-uniform arrangement of the pixels 120.
Specifically, as can be seen in FIG. 3 the depth D of the pixels
120 into the light guide 110, is non-uniform. The non-uniform
arrangement of the pixels 120 deters the generation of diffraction
gratings by the pixels 120.
[0048] FIG. 4 illustrates a top view of the one-way see-through
device 100 with a non-uniform arrangement of the pixels 120.
Specifically, as can be seen in FIG. 4 the shape of the pixels 120
is non-uniform. The pixels 120 may have shapes of lines, circles
(dots), or polygons, for example, as see in the plane of FIG. 4.
The non-uniform arrangement of the pixels 120 deters the generation
of diffraction gratings by the pixels 120.
[0049] Size, depth and placement of the pixels 120 are important
factors for producing "invisible" one-way see-through illumination
in implementations according to the inventive concepts disclosed
herein. This means in some implementations the method being
deployed to render the pixels 120 may possess the resolution and
placement precision to "print" light-diffusive pixels that are
below 15 microns in size. For example, one desirable method is
capable of capping a 2 micron wide light diffusing layer 124 with a
matching light reflecting layer 122 to impart one-way light
emission. In some implementations according to the inventive
concepts disclosed herein, even small areas of low density
traceless transparent illumination for a display may require the
placement of millions of pixels in practice. For example, one
square inch of a 20% halftone of two micron wide one-way
light-transmitting square pixels contains more than about 32
million pixels, whereas ten micron wide pixels (at a 20 percent
halftone) would have about 1.3 million pixels per square inch.
[0050] The arrangement of the pixels 120 to be non-uniform in the
design of the device 100 may be accomplished through an appropriate
selection of pixels 120 to be formed on the light guide 110.
Methodologies are discussed further below.
[0051] In some implementations, fully transparent illumination
production requires a methodology capable of producing pixel arrays
that avoid the generation of diffraction gratings that impede
vision. Diffraction gratings are formed by the uniform placement of
pixels, which could be lines, circles (dots), or polygons that
generate wave interference patterns that result in separation of
composite light (white light) into its components (different
colored light). To avoid this effect, when applying micron scale
one-way light-emitting pixels to a surface for the purpose of fully
transparent illumination, a "random" pixel pattern may be deployed
when rendering the light-reflective pixel layer. In other
embodiments according to the inventive concepts disclosed herein, a
pixel size of less than a wavelength of light in width can be
rendered that lack the sizing to cause the wave interference
patterns that generate diffraction gratings.
[0052] Considerations regarding generating an effective "random"
light-reflective pixel pattern to avoid the creation of a
diffraction grating are as follows. A light reflecting layer 122
pattern should accurately cap a light diffusing layer 124 pattern.
Thus, the coordinates of any randomized light reflecting layer 122
pattern should be known, so the related underlying light diffusing
layer 124 pattern can be generated. In implementations according to
inventive concepts disclosed herein, both the light reflecting
layer 122 pattern and the light diffusing layer 124 pattern are
produced using microlithography printing plates. Such
microlithography printing plates may be formed using customizable
microlithography CAD applications, such as used within the
semiconductor industry.
[0053] Regarding pixel 120 pattern specification, current
semiconductor CAD software repeats geometries by "stepping" a
pattern across a wafer surface. To generate random pixel locations
that prohibit diffraction gratings repeated patterns should be
avoided. Accordingly, according to disclosed embodiments of the
inventive concepts disclosed herein, random pixel locations may be
assigned across the entire surface area of a display (device) by
specifying the parameters of pixel 120 width. After specifications
are inputted, a random number generator is used to test for the
availability of spaces of the display (device) surface until an
entire pattern is formed.
[0054] In some embodiments according to the inventive concepts
disclosed herein, the optimum pixel pattern of the pixels is
generated by the random placement of pixels 120 with no overlap.
Further, the light reflecting layer 122 of each pixel 120 may be
slightly wider than the underlying light diffusing layer 124 for
the pixel.
[0055] The illumination surface 142 of the light guide 110 may be
coated with an anti-reflection coating whose composition and
thickness is optimized to prohibit the reflection of the selected
illumination color. FIG. 5 illustrates a side view of a one-way
see-through illumination device 500 according to the inventive
concepts disclosed herein having an antireflection coating 510
disposed on the illumination surface 142 to reduce reflection of
light from the pixels 120 directed to the illumination surface 142.
The device 500 of FIG. 5 is similar to that of FIG. 1A, except for
the addition of the antireflection coating 510. The antireflection
coating 510 may be optimized for a specific wavelength of light or
address reflection across a broad spectrum. The antireflection
coating 510 improves night operation of the display by limiting
light emission from the non-illuminated side of the display, for
example a 3% light reflection rate can be lowered to less than
1%.
[0056] The embodiments of the inventive concepts disclosed herein
have been described in detail with particular reference to
preferred embodiments thereof, but it will be understood by those
skilled in the art that variations and modifications can be
effected within the spirit and scope of the inventive concepts.
[0057] Embodiments of the inventive concepts disclosed herein have
been described with reference to drawings. The drawings illustrate
certain details of specific embodiments that implement systems and
methods of the present disclosure. However, describing the
embodiments with drawings should not be construed as imposing any
limitations that may be present in the drawings.
[0058] The foregoing description of embodiments has been presented
for the purposes of illustration and description. It is not
intended to be exhaustive or to limit the subject matter to the
precise form disclosed, and modifications and variations are
possible in light of the above teachings or may be acquired from
practice of the subject matter disclosed herein. The embodiments
were chosen and described in order to explain the principals of the
disclosed subject matter and its practical application to enable
one skilled in the art to utilize the disclosed subject matter in
various embodiments with various modification as are suited to the
particular use contemplated. Other substitutions, modifications,
changes and omissions may be made in the design, operating
conditions and arrangement of the embodiments without departing
from the scope of the presently disclosed subject matter.
* * * * *